As shown in FIG. 1, which shows a prior art of the CPU heat dissipator hook up apparatus used on the ZIF socket (Taiwan Patent publication No. 246982). Both sides of the arm 1 are bent upward to provide the arm with a resilient means for increasing the assembling force with the other elements, and a holding portion 11 is formed downward at each end of the arm 1. A hole 12 is provided at the bottom of the holding portion 11 and two lugs 13 disposed upward at the opposite sides of the holding portion 11 are for the purpose of easier holding and moving. When assembled, the two lugs 13 are pressed toward the center of the arm 1 to allow the hole 12 of each of the holding portions 11 to be hooked with a bark 21 provided on the ZIF socket 2. The upward resilience of the arm 1 fixes a heat dissipator 4 on the CPU 3. When disassembled, again the two lugs 13 are pressed toward the center of the arm 1 and a force pressing the lugs 13 downward is also needed to allow the hole 12 of the holding portion 11 to disengagement from the bark 21 on the ZIF socket 2. After the above procedure is accomplished, the heat dissipator 4 is able to get off the CPU 3.
Above-mentioned prior technique suffers a major drawback which is that when the two lugs 13 are pressed toward the center of the arm 1, an extra space is needed for the operation of the lengthening arm 1 and besides that, the lugs 13 of the holding portions 11 generally are not easy to be pressed downward. Therefore, this kind of design is not comfortable for the user, especially when frequently assembling and disassembling is required.